The small volumes associated with micro high-pressure liquid chromatography require a layer thickness in the range of a few to approximately 100 .mu.m for a measuring beam having a cross section of one to a few mm.sup.2. Cuvettes with a layer thickness of this kind are known from the infrared analysis techniques with respect to liquids. Generally, these cuvettes have two windows made of parallel plates separated from each other by a spacer of a corresponding thickness. The arrangement is seated in a housing which in most instances is of cylindrical configuration. The housing has an inlet and an outlet for the liquid. Cuvettes of this kind are described in German Pat. No. 16 48 917 and in U.S. Pat. No. 3,090,861. These cuvettes have the disadvantage that they are somewhat difficult to manipulate and are difficult to reproduce because of the relatively thin spacer. Furthermore, it is difficult to make these cuvettes seal-tight for the pressures of 100 to 1,000 bar that are used in high-pressure liquid chromatography.
German Pat. No. 21 58 220 discloses a through-flow cuvette assembled with at least three parallel plates. The center plate has a cutout which defines the measuring space and the inlet and outlet of the cuvette. However, this cuvette is not suitable for a very small measuring volume, that is, for a very small layer thickness because then the center plate would have to be so thin that it cannot be produced or manipulated.